There is concern about the threat that nanoplastics (NPs) may pose to both wildlife and humans. This thesis explores the mechanisms of toxicity of polystyrene nanoparticles (PS-NPs) in chicken... Show moreThere is concern about the threat that nanoplastics (NPs) may pose to both wildlife and humans. This thesis explores the mechanisms of toxicity of polystyrene nanoparticles (PS-NPs) in chicken embryo. In Chapter 1, I review the literature on MPs and NPs, and their potential risks to humans and animals. In Chapter 2, I show that the exposure of chicken embryos to PS-NPs produces malformations in the neural tube, eyes, and tail. Chapter 3 details the heart malformations caused by PS-NPs. I propose that the mechanisms of PS-NP toxicity include the selective binding of PS-NPs to neural crest cells, leading to the death and impaired migration of those cells (Chapter 4). My data support this model, indicating that most of the malformations I observe are in organs that depend for their normal development on neural crest cells. My findings are a matter of concern given the large and growing burden of nanoplastics in the environment, and the fact that they are being considered as drug-delivery agents in nanomedicine. They also suggest that NPs may pose a potential health risk to the developing embryo. Further work is needed to determine how PS-NPs become distributed in the body. Show less
This thesis tapped into the details of speech production in Mandarin Chinese in the framework of current psycholinguistic models of speech production. The findings in this thesis not only... Show moreThis thesis tapped into the details of speech production in Mandarin Chinese in the framework of current psycholinguistic models of speech production. The findings in this thesis not only contribute to the understanding of the underlying neuropsychological mechanisms of speech production in Mandarin Chinese, but also provides insights into the understanding of the accountability of current models of speech production that are mostly based on evidence from West Germanic languages. Show less
